Our previous experiments in M. irus monkeys have shown that salivary antibody to a whole cell S. mutans vaccine will inhibit implantation of the organism in dental plaque. Monkeys will be locally immunized via the parotid duct with several purified antigens prepared from S. mutans. We will evaluate the effect of salivary antibody induced in this way on subsequent attempts to orally infect these animals and on caries incidence. Six groups of 4 monkeys each will be immunized with: 1) a crude enzyme (glucosyltransferase) preparation (CEP) fractionated from strain BHT culture fluid with 60% (NH4)SO4 containing 10 to the ninth power killed BHT organisms; 2) the CEP alone; 3) an enzyme preparation (HEP) obtained by hydroxylapatite fractionation; 4) an enzyme preparation obtained from HEP by isoelectric focusing; 5) dextran obtained from L. mesenteroides; and 6) "a-d" antigen obtained from strain HS6. Eight monkeys will serve as sham immunized controls. Serum and salivary antibodies will be assayed by: 1) indirect immunofluorescent staining (IFS); 2) inhibition of glucosyltransferase activity; and 3) inhibition of adherence to glass. When maximum salivary antibody titers are reached the monkeys will be orally infected with S. mutans. Plaque samples from 12 individual tooth surfaces will be examined at intervals by IFS and a separate plaque pool from each animal will be cultured. Results will be reported respectively as percent of infected surfaces and percent of total cultivable organisms identifiable as the infecting strain. S. mutans in plaque and antibody titers will be followed to demonstrate correlations. In vivo microscopic examinations, DMFS examinations and bite-wing radiographs will be used to determine incidence of caries. The ability of salivary antibody to cross-react in vitro with, and inhibit oral implantation of, heterologous strains of organisms will be examined. These results will provide information important to the future application of immunization in the prevention of human dental disease. BIBLIOGRAPHIC REFERENCES: F.G. Emmings, R.T. Evans, R. Hall and R.J. Genco. Effect of antibody to S. mutans on oral implantation of a non-cross-reacting strain in M. irus. I.A.D.R. abstracts 53: L-100, 1975. Annual Session I.A.D.R. April, 1975. London, England.